Rotary toothbrush



sept. 29, 1925.

A. SHAPIRO ROTARY TOOTHBRUSH Filed April 10. 1924 Patented Sept'. 29,1925.

UNITED STATES PATENT OFFICE.

ABE SHAIPIRO, 0F CHICAGO, ILLINOIS.

ROTARY TOOTHBRUSH.

Application mea apra 1o, 1924. serial No. 705,439.

brushes and contemplates, among its objects, a power driven device foruse with adetachable brush unit.

Other objects of my invention concern means for detachably supportingand journaling the brush unit or shank, a novel guard for the brush, andmeans for so holding the brush shank and its guard that theguardprotects the shank while the device isnot in use.

These and further objectsl and features are set forth in the followingdescription of a specific embodiment of my invention. In theaccompanying drawings which illustrate this embodiment,

Figure 1 is a front elevation of the devlce Figure 2 is an enlargeddetail partly in longitudinal section of the handle member and the brushshank;

Figure 3 is a transverse section of the brush and guard, taken on theline 3--3 of Fi re 2;

igure 4 is a'transverse vertical section through 'the handle membertaken on the line 4--4 of Figure 2; Figure 5 lis a transverse verticalsection through the 'bracket yand rack, taken on the line 5--5 of Figure1.

Fig. 6 is a transverse section through the handle member taken on theplane of the line 6 6 of Fig. 2, and

Fig. 7 is a similar view taken on ythe plane of the line 7--7 of Fig. 2.

A bracket 1Q, suitably secured to the wall of a lavatory as by screws11, supports a small electric motor 12 which is controlled by a switch13 conveniently located on the bracket. The armature of the motor isconnected within an axial boss 14 to the inner end of a flexible shaft15., At its outer end the flexible shaft carries a stationary sleeve 16beyond which protrudes the semi-cylin drical end 17 of the live shaft(see Fig. 6). The stationary sleeve 16 is inserted in a inventionrelates to rotary tooth counter-bore at the rearward end of a handlemember 18, and there secured bv a set screw 19. The projecting end 17 ofthe flexible shaft extends into the end bore of a small shaft or rotarymember 20, which is journaled 1n a bore 21 in the handle member 18.

The rotary member 20 is provided with a pin 22 for establishing adriving connection between'the flexible shaft and the rotary member.

At its forward end, the handle member has a counter-bore 23 which isclosed by a plug 24. The bore 25 of 'the plug rotatably and reciprocablyjournals a cylindrical head 2G at the inner end of a brush shank 27. Theinner end ofthe head 26 'is cut away on either side to leave a flatblade 28 (Fig. 7) which extends into a counter-bore or driving socket 29Iat the outer end of the rotary member 20, pins 30 being provided i toestablish a,driving connection between the rotary member and shank. Thehead of the shank is j urged outwardly by a coil spring 31 .disposedwithinthe bore 29 of the rotary member and contacting a washer or disk32 which, in turn, bears lagainst the inner end of the blade 28 of thehead.

The brush shank 27 comprises a-pair vof twisted wires secured at theirinner ends in the head 26, and supporting adjacent their `outer ends thespirally arranged transverse bristles which form a rotary brush 27. Thetwisted wires terminate in a ball 33 which cooperates `with a socket 34'at the outer end of a guard 35 to support and journal the outer end ofthe brush. The guard 35 is in the form of a shell, semi-cylindrical intransverse section, which closely embraces one side of the brush,leaving but a small longitudinal opening 36 through which a peripheralportion of the brush extends.

The inner end of the guard 35 is inserted in an arcuate slot 37 formedbetween the plug 24 and the shell-like end of the handle `member 18.Adjacent its inner end, the` guard is provided with a vrectangular hole38 for co-operatingwith a latch 39 pivoted at 40 within a suitableradial slot inthe plug 24 and pressed into the hole 38 by a spring 41.

When it is desired to detach the brush shank and its guard from the.handle member and to substitute another brush and guard, a manuallyenga able key 42', which extends through the s ell ofthe handle member,is pressed inwardly to release the latch `3S), permitting the guard tobe withdrawn from the slot 37. The head 26 1s then easily pulled fromthe bore .25 of the plug, and the shank thus` wholly disengaged from thedevice. Another shank 27 1s then inserted in the handle member, theblade 28 of the shank head passing between the pms 30 on the rotarymember 20 and compressing the spring- '31. Another guard 35 is theninserted in the slot 37, care being taken that the socket 34 of theguard embraces the ball at the outer end of the shank. When the handleis fully inserted and locked in place by the latch 39, the shank 27, itwill be noted, is also locked in place. The continual pressure of thespring 3l at all times holds the head 33 in the socket 34 to provide anouter journal for the shank and at the same time to hold the brushwithin the guard 35.

To use the device, the switch 13 is thrown to start the motor, which,through the fiev ible shaftv and rotary member 20, drives the brush. Asthe guard 35 is comparatively small it may easily be inserted in themouth between cheek and teeth to reach all the exposed portions of theteeth. The guard` of course, protects the flesh and gums from accidentalcontact with lthe brush` or with other. portions of the shank. Theflexible shaft permits the brush to be disposed at any convenient angleto reach the desiredteeth.

Attention is also called to the very short distance left between theouter end of they brush and the outer endofthe guard. This featurepermits ready access to the teeth at the back of the mouth, and also tothe inner or lingual surfaces of the-teeth. The thinness of theshell ofthe guard and its closeness to the brush facilitate the brushing ofexposed tooth surfaces all of the way to the gingival margin.

In order that cach member of the household may keep his individual brushand guard conveniently near the device, I `prefer to provide the bracket10 with a 4rack 43 comprising a plurality of sets of slots 44 -and holes45 thercbeneath. Each of these sets of openings is adapted to support abrush and its associated guard. The head of the particular brush sha-nk27 is inserted in one of the holes 45, while its guard 35 is -insertedin the slot 44 directly above the shank 27. In inserting the guard inthe rack the user presses the outer ends of the shank and guardtogether'so that the ball 33 is embraced by the socket 34. Once theguard is tightly insertedy in its supporting slot 44 in the rack,the.brush shankis supported and protected at its free end aga-instlaccidental bending or other injury. It is also to be noted that theguard is disposed above theshank and so completely envelopes it thatdust and soot can not accumulate on the v brush.

The angles of the slots 44 and 45 in the rack are preferably such thatthe shank 27 Vvmustbe sprung slightly to bring the ball into the socket34. This tends to bind the shank and guard in their respective openingsto further prevent their dislodgment. The bracket 10 also carries asub-bracket or yoke 46 on which the handle member 18 may be hung whenthe device is not in use. The rack 43`is preferably cut away as at 47for the reception of the forward endof the handle member to hold thelatter securely in place. t y

While I have shown this particular embodiment of ymy invention, I contemlate that changes may beimade therein wit out departing from the scopeand spirit of my invention. l What I claim is:

1. In a device of the class described, the combination of a handleportion,l a rotary member journaled thereon, means for driving saidmember, an outwardly extending shank disposed longitudinally of saidmember and having a driven connection therewith, means for journalingsaid shank at its inne:` end on said handle portion, a brush on saidshank, a bracket extending from said handle portion, co-operating thrustbearing means for said shank on the end thereof and on said bracket,andl spring means for urging said shank outwardly.

2. The combination in a rotary tooth brush of a handle member, a drivingmember rotatably journaled therein, a shank comprising bristles forminga brush, a ball,v

at the outer end of the shank and means at the inner end of the shankinsertable in said rotary member for making a driving connectiontherewith, a guard for said brush supported from said handle, a socketat the outer end of said guard for the reception of said ball, and meansfor urging said sha-nk outwardly to hold said ball against said socket.-

3. The combination in a rotary tooth brush of a rotary driving member, ahandle member for journaling said driving member, a shank, a brush onsaid shank, means for supporting the inner end of said shank and foreffecting a driven connection therefor with said driving member, aguard, co-operating means on the outer end on said shank and on saidguard for journaling the outer end of said shank, spring-pressed lockmeans on said handle adapted automatically to snap into lockingengagement with said guard when said guard is joined to said handle, anda manually engageable key for releasing said locking means.

4. The combination in a rotary tooth brush comprising a handle portionfor rotatably supporting the tooth brush and having an arcuate slot inone end thereof, of a guard for said rotary tooth brush comprising ashell of semi-cylindrical cross-section for embracing and vshieldin saidrotary brush, an end closure for sai shell having an inwardly facingsocket for supporting the brush, at its opposite end said shellhaving aslot engaging portion of arcuate crosssection adapted to be received insaid arcuate slot of the handle portion, said slot engaging portionbeing provided with a shoulder for (zo-operating with lock means carriedby said handle portion.

5. The combination in a rotary tooth brush, of a iiexible driving shaft,a handle portion at the eIid thereof, a brush journaled in said handleportion, a guard projecting from said handle portion and having abearing for the outer end of said brush, and a spring tending to thrustsaid brush forwardly to maintain thesame in said bear- The combinationin a rotary tooth brush, of a handle portion, a driving member in saidhandle portion, said driving member having a drlving socket, a brushreceivable in said socket and ada ted to be driven thereby, a guardexten ing from said handle portion and partially sur rounding saidbrush, a bearing at the outer end of said guard for the end of saidbrush, and a spring associated with said socket for thrusting said brushinto said bearing.

7. The combination in .a rotary Itooth brush, of a exible driving shaft,a handle at the end thereof, a rotary member in said handle driven bysaid shaft, said handle having a bearing plug in one end, said lughaving a uide bore therein, a brush adi; ted for adyustable mounting onsaid han le comprisin a shank, said shank having a cylindrica portionwhich has bearing supvreceivable in said soc et, a bearing for the outerend of said brush member carriedby said handle ortion and a spring insaid driving member reacting through said flatsided portion forthrusting said brush member axially. i

9. The combination in a rotary tooth brush, of a flexible driving shaft,a handle member at the end thereof, a driving element rotatablysupported in said handle member and connected to said shaft, a plugmember secured to said handle member, said plug member having a guidingbore therein,

a removable brush comprising a shank, said shank having'a cylindricalportion receivable in said guiding bore and having a driving extensionprojecting beyond said cylindrical portion and adapted to engage withsaid driving element, one of said members .having a recess thereindefinin an arcuate slot between itself and the ot er member, and adetachable guard having an end portion of arcuate cross section adaptedto be received in said arcuate slot.

In witness whereof, I hereunto subscribe my name this 8th day of April,1924.

ABE SHAPIRO.

